Podosphaera xanthii but not Golovinomyces cichoracearum infects Cucurbits in a Greenhouse at Salinas, California

Cosme Bojorques Ramos
Karunakaran Maruthachalam,
James D. McCreight
Raymundo S. Garcia Estrada

Traditionally, Erysiphe cichoracearum (now Golovinomyces cichoracearum) and Podosphaera xanthii, formerly Sphaerotheca fuliginea, have been reported as the causal agents of cucurbit powdery mildew (CPM) (2, 10). These two fungal species have often been misidentified (12), due to similarities in their anamorphic characteristics and the very scarce production of ascomata (13, 16), given that the ascocarpic structure was considered basic for earlier systematics. After considering the fibrosin inclusions in the conidia to differentiate S. fuliginea from E. cichoracearum in Australia and North America (1, 18), S. fuliginea was determined to be the predominant or the only CPM species in the United States (12), although both species can be found infecting the same crops (2, 8, 10).

Continue Reading